In a mass spectrometer, there are a number of methods of transporting liquid and solid samples to an ionization source. Above all, an explanation will be given as follows of sample introduction using a probe of introducing a sample directly to an ionization source or a vicinity thereof.
US 2010/0243884 A1 describes a method of introducing a probe holding a sample to a sample vaporizing chamber at a vicinity of an ionization source under a reduced pressure. According to the method, a sample is vaporized by heating the probe, and a sample gas is introduced to the ionization source by making a gas flow from the sample vaporizing chamber in a direction to the ionization source. The sample gas is ionized at the ionization source by an ion-attachment ionization or the like, and generated ions are introduced into a mass analyzer by an electric field.
Japanese Unexamined Patent Application Publication No. Hei10 (1998)-69876 describes a small heating sample probe for directly introducing a sample to an ionization source for electron ionization (EI). The probe has a metal wire at a tip end thereof, sampling is carried out by adsorbing the sample to the wire, and the sample is heated to vaporize by applying a voltage on the wire. After introducing the probe into a vacuumed chamber (10−3 through 10−4 Pa), a sample gas can be ionized by EI.
Analytical Chemistry, 2005, 77, 7826-7831 describes an atmospheric pressure solids analysis probe for introducing a sample directly to an ionization source for an atmospheric pressure chemical ionization (APCI). A sample is coated onto a tip end of a melting point capillary made of borosilicate and is inserted into a space where APCI is performed. The sample is gasified by blowing a high temperature gas to a sample coating portion, and a sample gas is ionized by a plasma generated by corona discharge. Generated ions pass through an orifice and are conveyed to a mass analyzer.